Electrochemical reactions based on oxidation or reduction (redox) of metals and compounds at an electrode are highly selective because of the characteristic redox potential at which oxidation or reduction of the electroactive species occurs. With electrochemical sensing, selection of the electrode material and electrolyte solution has been very important in determining sensitivity and selectivity. A detailed description of the theoretical considerations is contained in the above cross-referenced application and is incorporated by reference in this application to the extent required.
One limitation of the prior art is that the presence of hydrogen ions, either in the solvent or in the additive (electrolyte), will interfere with the oxidation and reduction of chemical agents sought to be detected. This had lead to the necessity for developing aprotic (free of replaceable hydrogen ions) electrolyte systems.